1. Field of the Invention
The present invention relates to a coating and developing system for coating a substrate, such as a semiconductor wafer or an LCD substrate, namely, a glass substrate for a liquid crystal display, with a resist solution by a coating process and processing the substrate by a developing process after exposure, a coating and developing method to be carried out by the coating and developing system, and a storage medium.
2. Description of the Related Art
A manufacturing process for manufacturing a semiconductor device or an LCD substrate forms a resist patter on a substrate by photolithography. Photolithography includes a series of steps of coating a surface of a substrate, such as a semiconductor wafer (hereinafter, referred to as “wafer”) with a resist film by applying a resist solution to the surface, exposing the resist film to light through a photomask, and processing the exposed resist film by a developing process to form a desired pattern.
Generally, those processes are carried out by a resist pattern forming system constructed by connecting an exposure system to a coating and developing system for coating a surface of a substrate with a resist solution and developing an exposed film. Such a resist pattern forming system is proposed in, for example, JP-A 2006-203075. In such a coating and developing system, an area in which modules for processing a substrate before the substrate is subjected to an exposure process, and an area in which modules for processing the substrate processed by the exposure system are vertically arranged in layers to further increase the processing rate of the coating and developing system, carrying devices are installed respectively in those areas to improve carrying efficiency by reducing load on the carrying devices so that the throughput of the coating and developing system may be increased.
As shown in FIG. 10 by way of example, this coating and developing system has developing blocks B1 and B2 that carry out a developing process, a coating block B4 that carries out a coating process for coating a wafer W with a resist solution, and antireflection film forming blocks B3 and B5 that form antireflection films before and after the application of the resist solution to the wafer W. The developing blocks B1 and B2, the antireflection film forming block B3, the coating block B4 and the antireflection film forming block B5 are stacked up in that order. The blocks B1 to B5 are provided with shelf units built by stacking up wet-processing units that carry out wet processes, such as coating solution application processes for applying chemical solutions to a wafer W for a developing process, a resist solution application process and an antireflection film forming process, and processing units that carry out processes before and after the wet process in layers, respectively, carrying devices A1 to A5 that carry a wafer W to and from the wet-processing units and the parts of the shelf units, and a transfer arm for transferring a wafer W to and from the blocks B1 to B5. The wet-processing unit has, for example, three wet-processing devices. The processing units include a necessary number of necessary types of units. Loads on the carrying devices A1 to A5 and the transfer arm are reduced to improve the throughput of the coating and developing system.
Such a coating and developing system can achieve a throughput of, for example, on the order of 180 wafers/hr. In some cases, a desired throughput is dependent on an intended process. In some cases a system capable of processing wafers at a high throughput in the range of 200 to 250 wafers/hr exceeding a throughput that can be achieved by the current systems is demanded, and in other cases, a system capable of processing wafers at a very high throughput is not demanded.
The throughput of the foregoing system may be improved by increasing the number of the wet-processing units of the developing blocks B1 and B2, the coating block B4 and the processing units. Such construction increases loads on the carrying devices A1 to A5, reduces carrying efficiency and hence it is difficult to improve the throughput of the system. If the number of the units of the blocks B1 to B5 is adjusted to achieve a desired throughput, the number of the units is dependent on the throughput. Therefore, many different types of systems respectively having different numbers of units need to be manufactured according to the demand of users, which increases loads on work for designing and manufacture.
The numbers of the wet-processing units and that of processing units may be increased by increasing the number of the blocks including the developing blocks B1 and B2 stacked in layers. However, a carrying in which the transfer arm carries a wafer W to and from the blocks extends vertically and the number of cycles of a transfer operation for transferring a wafer W to and receiving a wafer W from the blocks increases if the number of the layers of the blocks is increased. Consequently, load on the transfer arm increases and it is difficult to improve the throughput of the system. To cope with the change of the through put, the number of the layers of the blocks needs to be changed, the carrying range of the transfer arm needs to be changed and hence many types of systems needs to be manufactured. Likewise, it is difficult to reduce loads on work for designing and manufacture.